1. Field of the Invention
The present invention related to an electrically controlled brake system of a vehicle such as an automobile, and more particularly, to an improvement of an electrically controlled brake system of a vehicle so as to be shut down with a more prudent confirmation of the driver's will for resting the vehicle.
2. Description of the Prior Art
Generally in a vehicle such as an automobile, the ignition switch controls the supply of electric currents to all parts and devices of the vehicle adapted to be powered by its battery, except those devices such as time pieces, retention memories of a micro-computer and the like which need a continuous supply of an electric current and are therefore directly connected to the battery, so that the turn off of the key of the ignition switch instantly disables all those electrically operated parts and devices.
In this connection, however, it has been proposed by Japanese Patent Laid-open Publication based upon German Patent Application P 4421774.9 to prevent the ignition switch being turned off when a changeover valve of the brake system is being operated. Further, in Japanese Patent Laid-open Publication 6-127317 it has been proposed to let the motor of a pressure booster of the brake system be started by the brake pedal being depressed even when the ignition switch has been turned off.